BATTLE CREEK, Mich. — Gov. Jennifer M. Granholm expressed growing worry on Wednesday that an oil spill, believed to be among the largest ever in the Midwest, might reach Lake Michigan if efforts to contain the oil were not strengthened.

“It would be a tragedy of historic proportions if this reached Lake Michigan,” Ms. Granholm said.

More than 800,000 gallons of oil spilled Monday into the Kalamazoo River, a major waterway that flows into Lake Michigan, about 60 miles away. The leak came from a 30-inch pipeline that carries millions of gallons of oil each day from Griffith, Ind., to Sarnia, Ontario.

Response crews worked Wednesday to contain the oil spill, which had already reached at least 35 miles of the river and left fish and birds coated in oil.

On the river on Wednesday, Dan Backus arrived at his favorite fishing spot and found black water and oil-soaked plants. Looking out at the damage from the spill, he mourned the loss of fish and vegetation.

Enbridge Energy Partners, the owner of the pipeline, said the cause of the leak was being investigated. Patrick Daniel, the chief executive of Enbridge, said he did not think the oil would reach the Great Lakes.

Enbridge is Canadian owned, but based in Houston.

On Wednesday, Enbridge officials said they were doubling the amount of boom on the river to more than 28,000 feet. They also planned to double the number of workers responding to the spill to more than 300.

Photo

Enbridge officials doubled the amount of boom on the Kalamazoo River to over 28,000 feet.Credit
Bill Pugliano/Getty Images

The pipeline remained closed as officials examined the piece of the pipeline where the leak occurred. Federal regulators issued an order on Wednesday saying the company could not reopen the pipeline without approval.

“Our intent is to return your community to its original state and the waterways to their normal state,” Mr. Daniel said at a news conference on Monday. “We do commit to doing that.”

The company had responded to criticism from Governor Granholm, who continued to plead for more resources to contain the oil.

Ms. Granholm criticized the company again on Wednesday evening, saying the response was still “wholly inadequate.”

She said the oil had gone farther than previously known, to Morrow Lake, a big lake near Kalamazoo.

Other officials also questioned Enbridge’s response. Representative Mark Schauer, a Michigan Democrat, said he was angry that it took Enbridge several hours on Monday to report the leak after it was discovered. He said he feared that the leak may have started earlier on Sunday and that the amount of oil in the river could be much more than the company’s estimate.

Officials from the Environmental Protection Agency said they were investigating the timeline of events surrounding the oil spill. They said Enbridge could be penalized with fines if they did not complete the containment and cleanup work.

In this city of about 54,000 people that is best known as the global headquarters of Kellogg Company, residents could still smell oil on Wednesday as black masses of goop streamed down the river. Chris Simmons, the vice mayor who had been leading the city because the mayor was out of town, called the spill “a horrible disaster.”

The city had worked hard over the years to restore the once dirty river, he said.

“This river has bounced back from being mistreated in decades past,” he said. “We even had bald eagles come back. Now this is such a setback.”

Officials have opened a rehabilitation center for birds and other wildlife.

Some people have been sickened by the strong fumes.

Enbridge has paid for at least 30 families to stay in hotels after they reported concerns about air quality and other problems after the spill. Rachel Campbell said the smell of oil woke her up at 3 a.m. on Tuesday.

Ms. Campbell, who is pregnant, lives about six blocks from the river in Battle Creek, and she said she had trouble breathing.

“My eyes were burning, and my nose was burning,” she said. “It smelled like a diesel tanker had turned over in front of my house.”

Enbridge paid for Ms. Campbell, her husband and their two children to stay at a hotel downtown.

But others were worried about whether the company would follow through with all their promises. David Pike, a 52-year-old auto mechanic who is building a home on the river, had his doubts.

“How long is it going to take them to clean it up?” he said. “Right now, I’m frustrated. If they don’t fix this, it will turn to anger.”

Environmental groups were frustrated as well to see another oil spill after the oil spill in the Gulf of Mexico. Danielle Korpalski, a regional coordinator for the National Wildlife Federation, said the group would watch to make sure the company restored the environment.

A version of this article appears in print on July 29, 2010, on page A13 of the New York edition with the headline: Michigan Governor Warns of Spill Threat. Order Reprints|Today's Paper|Subscribe